Emax

esynthesist wrote:

>If some of you succeed in creating hardware for the RS422 it would be 
>great that this library can be used. If some special hardware 
>specific library must be used I can get in trouble with freeware 
>licensing for EMXP... unless that library would be completely free 
>also.
>  
>
it's just using a standard windows USB serial port driver so far. in 
this case, you'll see it just as a normal USB serial port... if it needs 
something more than that, I could be slowed down a lot, as I have no 
windows driver experience.... will have to look more into it if need arises.
:-)

anyway - I ordered RS422 chips yesterday. should have them in a few 
days, I hope. then will experiment with the emax, and see what i can see.

>PS: the fact that the host must initiate the communication at 31.25 
>kbaud and then has to switch to 500kbaud is something to think about 
>when using external clocking.
>
hmmm... of course standard RS232 ports don't do 31.25 or synchronous.....
possibly the simplest thing to do is to tell the serial interface to run 
at 19.2k, and i can make that value actually set the interface to 31.25 
similarly, tell the interface to run at 115k, and I can make it run as a 
synchronous slave. I don't think that will cause problems in the driver 
side.

speaking of 31.25 - how did you select that? was it one of the standard 
baud options with your RS422 ports?

> I suppose and hope that even this 31.25 
>kbaud is clocked by the Emax to the Mac, so that the host doesn't 
>have to change from internal clocking to external clocking all the 
>time.
>  
>
naah... it probably does change.
but that's OK.
very simple to do on the AVR side. just need to change a bit in a 
register, and flush serial port buffers.....
:-)